witmyer



I N V EN TOR WH M Wz'tmyw;

Nov. 15, 1927. I H. M. "NITMYER ARTIFICIAL LIMB FileSl 2 6:

I WITNESSES Patented Nov. 15, 1927.

STATES:

' HARRY WI'IMYER, OEMANHEIM, rnnnsvrvanm, assrenoia or one-T IRD To 1 JACOB H NISSLEY nn ONE-THIRD o HARRY n. 'rnonzr, BOTH OF MANH IM.

1 rENnsY vAnIA.

Application filed July 31,

This invention relates to artificial limbs, more particularly to artificial feet of the inflatable type and constructed of inherently,

plied weight, are-action tending to assist the forward thrust of the body in a manner simulative of the natural foot in walking, therebynot only to'afford the wearer the utmost ipossible comfort. but to render the movements easier; and therefore less fatiguing. 1 I a How these andothe'r' advantages may be secured in actual practice will be readily apparent from the detailed description here- 'inaftcr of the'typical embodiment shown in the drawings, whereof Fig. I is a longitudinal sectional view of an artificial foot constructed in accordance with my inventlon.

F ig. II is a horizontal section taken as indicated by the arrowsIIII in Fig. I.

Figs. III, IV and V are detail-sections with the arrows IIIIII, IV-IV and V-V in Fig. I.

More especially from Figs. I and II, it will be observed that the structure illus trated has the general external configuration of the human foot. In practice I construct the limb hollow from suitable moldable material (preferably rubber) with consequent formation of an inner chamber 10 adapted to be inflated through a valved nipple 11 provided near the top of the ankle 12 for this purpose. At the latter region, the side walls 13, 14 are made comparatively thin (Fig. III) so as to yield readily to bending crosswise of the foot proper 15; while at the front 16 and rear 17 the walls are considerably thickened to strengthen the structure against collapse at said region, as well as promote its'capacity to re-act and thus assist the forward'thrust of the body in walking.

I The lower part of the heel 18 immediately adjacent thehollow of the foot,-is reenforced and stiffened internally by a transverse protuberance having the form of an integral ridge 19 that projects upward within the hollow 10 in line with the axis of the ankle, and joins the opposite side walls 13,, 14 in taken locally, respectively, in accordance- .enrrrrrcrar. LIME.

1926. Serial No. 126,149.

well rounded curves as shown in Fig. V. That portion of the wall which defines the ball of the heel 18 is made of uniform thickness as shown in Figs. I and II, so as to effectively absorb .the shocks of impact inscident towalking, and'm-ergcs rather abruptly with the reenforcements at 17 and 19. v.

-The foot proper 15is internally braced at appropriate intervals" along. its length by transverse buttress ribs 20, also integrally formed, that extend inward toward thel0ngitud inal center of the structure from 0pp0- site sldes. By reference to Fig. II it will be curves of very liberal radii, see Fig. IV.

Fixcept at the ribs 20, the top wall 22 of the instep and the sides 23, 2 1 are of uniform thickness, the same being also trueof the sole 25 throughout; i. e., up to the locality of the transverse ridge 19. The sides 23, 24

of the foot proper 15 are thus well re-enforced against the possibility of collapse under pressure from above, while a medial longitudinal area along 22 and 25 is left free to yield under the elasticity of the rubber in responding to longitudinal movements of the foot having their inception at the region of the ankle.

WVith inflation to the proper degree (determinable in practice by the weight which is to be sustained), it will be apparent that through the re-action of the compressive stresses initially induced in the various reenforced portions of the rubber in concert with the counter cushioning effect of the compressed air, an easy forward thrust is imparted to the body in close simulation of natural walking, the characteristic construction of the ankle incidentally permitting free sidewise fiexure as required. The wearer is thus afforded the utmost possible comfort and with the aid. of my invention may actually derive pleasurable enjoyment in walking over long periods without experiencing extreme fatigue or soreness.

For the purpose of protection and additional reenforcements, the structure is covered by a layer or skinof comparatively stout fabric 26 which may be readily incorporated incident to molding and vulcanizing.

2 a I t 1,649,773

2. An artificial limb formed hollow from. inherentlyelastic, flexible and resilientma terial, the walls of the structure being thickened in some regions and strengthened in others by integral internal buttress ribs for sustenance against collapse and for capacity to yield to flexure to different extents in such reenforced regions. 7

3.- An artificial limb formed hollow from inherently elastic, flexible and resilient material, the walls of the structure being strengthened internally by integral tapering buttress ribs extending in-some regions entirely across the hollow and in other regions only part way across for capacity to yield to flexure to different extents in such reenforced regions. a

4:. An artificial foot formed hollow from inherently elastic, flexible and resilientmaterial the walls of the structure having transverse but ress ribs and being thickened at the front and rear regions of the ankle for relatively greater resistivity to forward 'and rearward bending than to sidewise 5. An artificial foot formed hollow from and rearward bending than to sidewise flexme, and the sole likewise reinforced by an integral upstanding transverse ridge lying in the line of the axis of said ankle.

6. An artificial foot formed hollow from inherently elastic, flexible and resilient material with integral buttressing ribs joining the sole with the side walls at intervals lon against collapse and for capacitytoyield to flexure to different extents in such reinforced regions.

7. an integral artificial limb having capacity for inflation to sustain determined weight andregionally thickened by lateral ribs for re-action in conformity with the lllOTOlilEIltS of the natural limb. V V

8. An. integral art ficial foot having capacity for inflation to sustain determined "I g it and laterally thickened at intervals across the lower portion in varying extent as well as in the region of the ankle so as to re-act in conformity with natural foot movewent a at to assist forward thrust in the act of walinir 7 In test niony whereof, I have hereunto signed my name at Manheim, Pennsylvania, this 27th day of July, 1926.

' HARRY M. WITMYEB.

'thwise of the foot proper for sustenance 

